Inflammatory responses to offending stimuli are known to be promoted by products of arachidonic acid metabolism. These products include leukotrienes and prostaglandins. The initial step in the "arachidonic acid cascade" involves the release of arachidonic acid from phospholipids or from triglycerides. The enzymes catalyzing such release of arachidonic acid include phospholipase C and phospholipase A.sub.2.
Inhibitors of phospholipase C and phospholipase A.sub.2 may be valuable therapeutic agents having wide applicability in inflammatory and allergic conditions in mammals. Although some currently available anti-inflammatory agents show inhibitory activity against these enzymes of the "arachidonic acid cascade", there is a continuing need for safer and more effective agents capable of treating inflammatory and allergic diseases.